The use of fluorinated silanes, i.e., silane compounds that have one or more fluorinated groups for rendering substrates such as glass and ceramics oil and water repellent are known. For example U.S. Pat. No. 5,274,159 describes destructible fluorinated alkoxy silane surfactants that can be applied from an aqueous solution. WO 02/30848 describes compositions comprising fluorinated polyether silanes for rendering ceramics oil and water repellent.
EP 797111 discloses compositions of alkoxysilane compounds containing perfluoropolyether groups to form antifouling layers on optical components. Additionally, U.S. Pat. No. 6,200,884 discloses compositions of perfluoropolyether-modified aminosilanes that cure into films having improved water and oil repellency and anti-stain properties.
EP 789050 discloses the use of fluorinated polyether silanes for making composite film coatings. U.S. Pat. No. 3,646,085 teaches fluorinated polyether silanes for rendering glass or metal surfaces oil and water repellent. WO 99/37720 discloses fluorinated polyether silanes for providing antisoiling coating to antireflective surfaces on substrates such as glass or plastic. U.S. Pat. No. 3,950,588 discloses the use of fluorinated polyether silanes to render ceramic surfaces such as bathroom tiles or cookware water and/or oil repellent.
Although many fluorinated silane compositions are known in the art for treating substrates to render them oil and water repellent, there continues to be a desire to provide further improved compositions for the treatment of substrates, in particular substrates having a hard surface such as ceramics, glass and stone, in order to render them water and oil repellent and easy to clean There is also a need for treating glass and plastic as a hard surface, particularly in the ophthalmic field, in order to render them stain, dirt and dust resistant. Desirably, such compositions and methods employing them can yield coatings that have improved properties. In particular, it would be desirable to improve the durability of the coating, including an improved abrasion resistance of the coating. Furthermore, improving the ease of cleaning of such substrates while using less detergents, water or manual labor, is not only a desire by the end consumer, but has also a positive impact on the environment. Also, it is desired that the coatings show particularly good chemical resistance, in particular when exposed to various cleaning compositions with a pH greater than 9. The compositions can conveniently be applied in an easy and safe way and are compatible with existing manufacturing methods. Preferably, the compositions will fit easily into the manufacturing processes that are practiced to produce the substrates to be treated. The compositions preferably also avoid the use of ecologically objectionable components.